Process and apparatus for grinding material and extracting volatile matter therefrom



June 24, 1930. H. w. MOIR 1,766,447 rnocnss mm APPARATUS ron anmnmsMATERIAL AND nxwmcwme vou'nma n'rma wunnnmou Original Filed Feb. 20 1926INVENTOR. Hank) W. [Va/r A TTORNE Y.

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Patented June 24, 1930 UNITED STATES PATENT OFFICE HARRY WIL SON MOIR,OF IiOS ANGELES, CALlIFORNIA PROCESS AND .APPARATUS FOR GRINDING-MATERIAL AND EXTRACTING VOLATILE MATTER THEREFROM Application filedFebruary 20,1926, Serial No. 89,679. Renewed August 12, 1927.

This invention relates generally to grindmg and calcining apparatus andto processes for grinding, calcining, dehydrating, and collectingvolatile matter from hydrous and simultaneously grinding and calciningmineral ores such as gypsum to form plaster of pans; for simultaneouslygrinding and dehydrating coal and similar fuels to form powdered fueladapted to be sprayed and ignited in the power plants of buildings,mines, locomotives, steamships, etc.; for grinding and heating as halticnuclei; etc. he grinding apparatus disclosed herein is not new. Myinvention resides in the application to any suitable standard grindingmachine of: being and. means for controlling the temperature of theheating means as applied to the material being ground; and means forremovmg and collecting water and other'volatile matter released from thematerial being ground, during the simultaneous grinding and heatinthereof; Particularly, my; invention resides in the installation ofelectric heating elements in the grinding plates of attrition grindingmachines, and in automatlcally controlling the temperatures of theseheating elements and plates. With my invention, it is possible toautomatically maintain the grinding plates at a constant temperature andto raise the temperatures thereof much higher than is possible with anyother available heatin agencies.

The addition of electrica heating elements to attrition grinders of thetype disclosed hereinroduces the most remarkable results: or example;duce it to powder means for heating the materia form, it is found that,

- when the temperature of the grinding plates for,

It is particularly designed for:

bituminous shales to. separate then volatile contents from theirground,during the grinding thereof,

in grinding coal to re the cold-setting of the machine holds for everysubstance I have run through the electrically heated machine. Thereasons for this result can only be guessed at, since it is not possibleto determine just what chemical or physical changes take place betweenthe plates during the operation of the machine. It is thought, however,that the intense heat, vaporizes or decomposes the water contents and.water ofcrystallization into its gaseous components and explodes thesolid nuclei into a multiplicity of still smaller particles.

Raw gypsum ground by this machine, at around five hundred degrees F.,emerges much finer than any-plaster of'Paris heretofore made, andcan beused immediately,

without ageing or the addition of retardants,

to form an exceedingly hard, white, and ala baster like plaster capableof being polished. It has also been found that iised plaster of Pariscan be revitalized and used over repeatedly by running it through thismachine at high temperatures, and that the revitalized product issuperior in every respect to the plaster of Paris resulting from thepreviouslyknown methods of reducing raw gypsum to the plaster of Parisform.

These are only a few instances of the remarkable results obtained by theuse of this invention and discovery. It has been successfully used tocrack gasoline from crude oil, .to extract oil from shale, to powder amixture of shale and gypsum to form an extremely hard hydraulic cement,to roast coffee berries and produce apulverized coffee ready for instantuse by merely dropping it into boiling water, to form very hard andwhite cements from different mixtures of gypsum and various salts, andmany other products.

I The operation of grinding is, of itself, a heating operation, and muchof the ordinary calcination of ypsum and similar ores is effected.solely y'repeated and prolonged grindings, with tests after eachgrinding to determine the water content of the ground product. Theoldgrinding method of calcination is a time-consuming operation,

which, in the case of gypsum, oftenrequires hours, in order to reducethe gypsum to plaster of Paris. With my invention and discovery, thecalcination of gypsum involves but one grinding operation extending overa few seconds, since the desired proportion of water contents of thegypsum can be removed at once by merely regulating the temperature ofthe grinding plates of my apparatus and by aspirating the water vaporand other volatile products from the electrically heated material duringthe grinding and exploding thereof.

It must be understood that my invention is not to be considered aslimited in any way to the grinding or calcination of any particularmaterial, or to processes for extracting any particular by-products fromthe material being ground. The application of electrically generatedheat and the subjec tion of the material being processed to such heatduring the grinding thereof, renders the machine and the processesinvolving its use practically unlimited in its uses.

In the drawing Figure 1 is an elevation of my apparatus, parts thereofbeing shown in section;

Figure 2 is an elevation of one of the grinding plates of the apparatus;and

Figure 3 is an elevation of the other grinding plate.

As shown in the drawing, my invention comprises a base member 1 on whichis mounted the grinding apparatus having the grinding disks 2 and 3located immediately over the discharge hopper 4, formed in the basemember 1. These grinding disks 2 and 3 are fixed, to rotate in oppositedirections about alined axes, on the shafts 5 and 6, respectively,rotatably mounted in suitable bearings 7, 8, 9 and 10. The bearingstandard 7 is adapted to be slid lengthwise on the member 1 by means ofthe well-known worm and gear construction 11, operated in the usual wayby the hand wheel 12, and to carry with it the shaft 5 and disk 2, inorder to provide access to the grinding mechanism whenever it becomesnecessary to renew, remove, or repair the parts thereof, or to adjustthe grinding disks relatively to one another to vary the fineness ofgrinding. As so far described, this apparatus is old and wellknown inthe art.

The grinding disk' 2 is provided with an annular recess 13 shaped toreceive snugly the annular grinding plate 14, the disk and plate beingdetachably secured together by the usual bolt and nut connections. Anelectric heating coil 15 is located in an annular recess 16 in disk 2between the plate and disk, and is connected for energization by meansof the wirm 17 to the collector rings 18, suitably fixe on the shaft 5and insulated therefrom. Brushes 19 are supported in contact with therings 18 on an insulated bracket 20 extending laterally from the bear-1ng standard 8, and wiring 21 connects these brushes 19, through therheostat 22 to any suitable source of electrical energy.

The disk 3 is formed centrally as a convex spider hub 23 provided withapertures 24, and the disk 2 is correspondingly concaved to receive thehub 23 and to form therewith a chamber 25 adapted to communicate withthe feed hopper 26 through the said apertures 24.

The disk 3 is also provided with an annular recess 27, in which isarranged the heating coil 28, connected by wiring 29 to the collectorrings 30 fixed to and insulated from the shaft 6. Brushes 31 in contactwith rings 30 are supported from the insulated bracket 32 extendinglaterally from the bearing standard 10, and wires 33 connect thesebrushes 31 through a rheostat 34 to any suitable source of electricalenergy.

The grinding plate 35 is adapted to be de-' tachably fixed to the disk 3in any suitable manner, and to be heated by the coil 28 to any desiredtemperature.

The usual feed gearing 36 of the hopper 26 is adapted to be operated bythe pulleys 37 and 38 and the belt 39 from the shaft 6, and motors 40and 41 are suitably connected to the shafts 5 and 6, respectively, torotate them and their grinding disks in opposite directions.

In order to collect the gaseous vapors and other volatile by-productsresulting from the grinding and heating of material in this apparatus,there-is provided a collector hopper 42, connected by any suitablesystem of conduits to a condenser or any other instrument or apparatusdesigned to collect or utilize said by-products. This hopper 42 isconnected by conduits 43 and 44 to the apertures 45 and 46,respectively, formed in the housing 47, the several parts of which aredesigned to provide ready access to the grinding mechanism.

The conduit 43 is provided with a support 48 carrying a motor 49 adaptedto operate a blower 50, which may be regulated either to draw onlygaseous or the lighter volatile products from the material being ground,or to draw over particles of any desired weight and to feed thismaterial to the collector hopper 42, or wherever desired. When thisblower apparatus is adjusted to withdraw only groundparticles of a givenweight, the endless conveyor C is arranged below the hopper 4 to carryofi allthe heavier particles from the grinding members. vWhen theapparatus-is adjusted to carry off only gaseous or the lighter volatileby-products, the conveyor C ma be omitted and the ground productdischarged directly from the hopper 4.

grinding disks and to maintain them, at any desired constanttemperature, each grinding In order to control the temperatures of the Idisk is provided with a recess 51 in which is arranged a thermostaticcontrol element'5l' of any well known type and having one end thereoffixed to the heating element, with the free end of said element fixed toone end of a wire 52 extending from said free end through an axial boreof the shaft 5 or 6, as the case may be. The other end of wire 52 isconnected rotatably to the lever arm 53 of an indicator 54 mounted toswing around a pivot 55 over the scale 57 A lever 58, mounted to pivotabout the pivot 59, has its lower arm 60 perforated to permit the wire52 to pass freel therethrough and to be engaged by c amping members '61,52 and adapted to be secured in adjusted positions thereon by means ofthe set screws 62. The ends of the clamping members next to the arm 61are made spherical in order to permit the lever arm 60 to swing aboutits pivot 59 as the wire 52 may be moved by the thermostatic element51'.

The lever 58 has its upper end provided with a slot 63 adapted toreceive slidably a f to the lower lever arm of the pin 64 fixed rheostatcontrol lever 65, which is mounted on the rheostat 22 to pivot about thepivot 66 and to swing over the contacts 67. As the thermostatic controlis identical for each grinding plate, the several. parts of each controlhave been designated by the same reference characters without describingthe specific connection of said parts to each plate.

It is to be understood that either grinding plate may be held'stationaryand that the grinding operations may be effected by rotating one plate.only .relative to the fixed plate. In the small capacity commercialmachines only one plate is rotatable. In any case, each plate of myapparatus should be equipped with electrical heatin elements and thethermostatic control there or. Each thermostatic element 51 is designedto bend or curl inwardly toward the plate opposite to the one carryingit, and this bending draws the wire 52 inwardly to make the indicator 54traverse the scale 56 and indicate the temperatures of the heatingelements or plates. i

'In order to effect the automatic control of the temperatures: instarting up the machine, the set screws 62 are loosened on the members61 and the rheostat arm is swung over to a contact 67 corresponding tothe temperature desired. When the desired temperature has been reached,as indicated on scale 56, the clamping members 61 are slid up on wire 52to contact with each side of the arm 60 and are fixed to the wire 52 bythe set screws 62. It will be obvious that increase or decrease oftemperature of the heating elements will move the wire 52 in onedirection or the other, and, through the arm 58, will move the rheostatlever 65 to slidably mounted on the wire,

comprising a decrease or increase the supply of electrical heatingenergyto the heating elements and thereby'maintain the temperatures of saidelements at the constant temperature shown between said platesduring themovements thereof, and non-fluid means carried by each of said platesfor heating them.

2. Grinding and dehydrating apparatus comprising a pair of plates havingopposed grinding surfaces, means for moving said plates relative to eachother, means for feeding material between said plates during themovementthereof, non-fluid means carried by each of said plates forheating them, and means for controlling the temperature of said heatinmeans. I

3. Grinding and dehydrating apparatus comprising plates having opposedgrinding aces, means for moving one of said plates relatively to theother, means for feeding material between said lates during the relativemovements thereof, andnon-fluid means carried by one of said plates forheating it.

4:. Grinding and dehydrating apparatus comprising plates having opposedgrinding faces, means for movin said platesrelative .to each other,means or feeding material between said plates during the relative movebyeach of said plates for heating it.

5. Grinding and dehydrating apparatus comprising relatively movablegrinding plates having opposedgrinding faces, and non-fluid meansconnected to one of said plates to heat it. p 6. Grinding anddehydrating apparatus relatively movable comprising plates havingopposed rinding faces, and non-fluid means connected to each of saidplates to heat them.

7. Grinding and dehydrating apparatus comprising a plurality of plateshaving opposed grinding faces and mounted to rotate about a common axisof rotation, means for rotating said plates in opposite directions,means for feeding material between the grinding faces of said plates,and non-fluid means for heating said plates.

8. Grinding and dehydrating apparatus pair of plates having opposedgrinding faces, means for rotating said plates relatively to each other,means for feeding material between said grinding faces, non-fluidheating means carried by said plates to heat them,'and means forconcomprising p ates having opposed grinding and dehydrating apparatustrolling the member,

faces, means for rotating said plates relatively toeach other, means forfeeding material between said grinding faces, and an electric heatingelement in one of said plates.

10. Grinding and dehydrating apparatus comprising plates having opposedgrinding faces, means for relatively rotating said plates, means forfeeding material between the rinding faces thereof, and an electricheating element in each of said plates.

11. In combination with the apparatus set forth in claim 9, means forcontrolling the temperature of said heating element.

12. The combination with the apparatus set forth in claim 10, of meansfor controlling the temperatures of each heating element.

13. In a grinding machine, a grinding member, non-fluid means carried bysaid member to heat it, means controlling the temperature of saidheating means, and means connected to said heating means to indicate thetemperature thereof.

14. The instrument set forth in claim 13 in combination with meansconnecting the indicating and controlling means to maintain thetemperature of the heating means at any desired constant temperature.

15. In a grinding machine, a grinding1 member, an electric heatingelement carrie by said member to heat it, a rheostat contemperature ofsaid element, and means connected to said element to indicate thetemperature thereof.

16. The combination with the instrument -set forth in claim 15 of meansconnecting the rheostat and the temperature indicating means to maintainthe heating element at any desired constant temperature.

17 In a grinding machine,

non-fluid means carried by said member to heat it, and means adjustablyconnected to said heating means to control the temperature thereof andto maintain the heat thereof at any desired constant temperature.

18. In grinding apparatus, a plurality of grinding members havingopposed grinding faces and mounted to rotate in opposite directionsabout a common axis of rotation, a heating element carried by each ofsaid plates means independent of each other to control the temperatureconnected to each element to indicate the temperatures thereof.

19. The combination with the apparatus.

set forth in claim 18 of means adjustably connecting the temperaturecontrolling and indicating'means to maintain the temperature of eitheror both elements at any desired constant temperature.

20. That. process of comminuting material which consists in grindin thematerial, spatially confining the material during the grinding thereof,and applying heat at a a grinding P of each element, and means allybored, grinding members fixed to said shafts with grinding faces opposedto each other, a heating element in each member, a thermostat connectedto each element, a temperature indicator outside each shaft, and meanspassing through the bore in each shaft to connect each thermostatoperatively to one of said temperature indicators.

22. Grinding apparatus comprising a support, a pair of axially bored andalined shafts, grinding members fixed to each shaft with grinding facesopposed to each other, a heating element in each member, means outsideof each shaft and passing through the bore thereof to control thetemperature of each element, a temperature indicator outside each shaft,and thermostatic mechanism passing through the bore of each shaft toconnect a temperature indicator operatively to each heating element.

23. The combination with the apparatus set forth in claim 22 of' meansadjustably connecting each temperature indicator to a temperaturecontrolling means to maintain thetemperature of either or both elementsat any desired constant temperatures.

24. Grinding apparatus c mprising opposed grinding members, el ctricalmeans for heating each of said members, and settable means connected tosaid heating means to predetermine the temperatures of said heatingmeans and to maintain sa d heating means at any of such predeterminedtemeratures as desired.

- In testimony whereof I have signed my name to this specification.

HARRY WILSON Mom.

